Automatic screw-cutting die



(No Model.)

W. vPORTEOUS. AUTOMATIG SCREW CUTTING DIE.

No. 427,908. I Patented May 13, 1890.

jrzv enfcu' 49% by W177i LTHU.,WASHING7ON n c UNITED STATES PATENT()FFICE.

XVILLIAM PORTEOUS, OF CINCINNATI, OI'IIO.

AUTOMATIC SCREW-CUTTING DIE.

SPECIFICATION forming part of Letters Patent No. 427,903, dated May 13,1890.

Application filed November 4, 1889. Serial No. 329,124. (No model) Toall whom it may concern.-

Be it known that I, WVILLIAM PORTEOUS, a citizen of the United States,residing at Cincinnati, in the county of Hamilton and State of Ohio,have invented certain new and useful Improvements in AutomaticScrew-Cutting Dies, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, formingapart of this specification.

My invention relates to that class of dies to be used as lathe-tools andinserted in a sliding head, usually a monitor, to be advanced up to andoperate upon the work, which is secured to and revolved by thelat-hespindle.

It has for its object an improved construction by which, when the threadhas been cut to the proper distance, the cutters are automaticallythrown apart to release the work from their action. I

The novelty of my invention will be hereinafter set forth, anddistinctly pointed out in the claims.

In the accompanying drawings, Figure l is a front elevation of a dieembodying my invention. Fig. 2 is a rear elevation of the same. Fig. 3is a side elevation of the same, partly in section. Fig. 4is a plan viewof the die.

The same letters of reference are used to indicate identical parts inall the figures.

The body of the tool is composed of a vertical face-plate A, from whichprojects horizontally a shank 1-3, for insertion in the sliding head towhich it is locked.

A central recess O is formed through the face-plate and back into theshank to receive a sliding and partially-turning thimble D, interiorlythreaded and provided with a pin a, which. projects up through aninclined slot b, Figs. 3 and 4, in the shank, as shown.

Screwed intothe thimble D is a tubular plug E, interiorly threaded toengage a jamscrew F, which is inserted through it and bears at its rearend against the inner wall of the thimble to lock the plug when adjustedin the thi1nble,as will be readily understood.

Pivoted at their lower ends upon the front of the face-plate A, as atcl, are two jaws G G, which, when brought together in a verticalposition, have a central opening 6 coincishank.

Secured in the jaws G G and adjustable by set-screws f are four cuttersH, projecting into the opening 6 and constituting the screw-cutting die.

while 1 have shown the cutters to be each independently adjustable, thedie may be in two parts and of the shape usually employed inscrew-cutting and with each half adj ustable. The upper ends of the jawsG G are preferably provided with grasping-handles g, to draw the jawstogether after they have been automatically thrown apart to the positionindicated by the dotted lines of Fig. 1, and 71 71 are stop-rods securedto a lug 1' upon the face-plate and passed through perforationsin thehandles g, and having buttons or heads upon their outer ends to arrestthe jaws when thrown open. I is a stop-sorew secured jaws in properposition when drawn together, as well as to support the upper ends ofthe jaws against torsion, Projecting from the rear upper side of the jawG is a lug j, in which is pivoted a latch 70, normally pressed forwardby a spring Z, and having serrations or engaging points, which, when thejaws are brought together, engage with a similarly serrated or notchedadjustable arm a, secured to .a lug 0, projecting from the upper rearside of the jaw G, in such manner as to hold the jaws firmly lockedduring the operation of the die. A spring 19, secured to the under sideof the face-plate, has its two ends extending up and engaging undertension the inner sides of the lugsj 0.

\Vhile I have shown but one spring, it is evident that there may betwo-one for each jaw.

Pivoted, as at r, to the shank B, and as a s to an upper rear projectionof the face plate, is a vertical trigger-piece J, having a lower rearextension or curved finger 15 engaging the rear side of the pin a.

When the jaws are locked together, the

finger it bears againstthe pin a, holding it in the forward extremity ofthe slot 1).

Now, when the tool is advanced to the revolving work and the thread hasbeen cut to the proper distance, the further advance of dent with therecess C in the face-plate and in the faceplate, and serving to arrestthe' latch 7e bears against the trigger J, and the the tool causes thework to come in contact with the plug E, which by frictional contact issimultaneously turned and forced back thereby, and through the medium ofthe thimble F moves the pin a. and vibrates the finger If andtrigger-piece J and thus forces the latch k out of engagement with thearm 12, and thereby frees the jaws, which are at once thrown apart bythe action of the spring 1) to the position shown by the dotted lines ofFig. 1. This throwing apart of the jaws frees the work from the cutters,and in cases where there is a shoulder at the end of the thread preventsthe stripping orinjury of the cut thread. By adjusting the plug E thejaws can be thrown apart for shorter or longer threads, as desired.

Having thus fully described my invention, I claim-- 1. In a die, thecombination, with a recessed face-plate and shank, of two pivoted jawscarrying the cutters and he] d together against spring-tension, a lockfor said jaws, and a trigger for breaking the lock, operated by the workto automatically release and throw the jaws apart, substantially asdescribed.

2. In a die, the combination, with a recessed face-plate and shank, oftwo pivoted jaws carrying the cutters, a lock to hold said jaws togetherin proper working position, a spring put under tension by the lockedjaws, a trigger for the lock, and a plug within the recess, providedwith means for pressing the trigger to break the lock, substantially asdescribed.

In a die, the combination and arrangement of the face-plate A and shank15, provided with recess (1, jaws G G, pivoted to the faceplate andcarrying cutters II, the spring p, engaging said jaws, the notched bar aand spring-latch 71;, the trigger J, and the thimblc F, with itsadjustable plug E, and pin a, eugaging the trigger J, substantially asand For the purpose specified.

Witnesses:

(mas. M. lnok, Faun IIOLZ.

